Engine Displacement Calculator
Enter the bore size, stroke length, and the number of cylinders to calculate the engine displacement.
How to Calculate Engine Displacement
The displacement of a piston engine is the volume defined by the travel of all of its pistons as they travel from the bottoms of their strokes (also known as bottom dead center or BDC) to the tops of their strokes (top dead center or TDC). Displacement is also known as the “swept volume” of the engine.
Displacement is used to indicate the size of an engine and can also be used to calculate the compression ratio of an engine.
The formula to find engine displacement is:
displacement = π / 4 × b2 × s × c
Where b is equal to the bore size, s is equal to the stroke length, and c is the number of cylinders.
For example, let’s calculate the displacement for a motor with a bore size of 3.4″, a stroke length of 3.6″ and 8 cylinders.
displacement = π / 4 × 3.4″2 × 3.6″ × 8
displacement = 0.78539816339 × 11.56 × 3.6 × 8
displacement = 261.48 cu in
Engine displacement can be measured in liters, cubic centimeters, or cubic inches. If the bore and stroke measurements are in inches, then the result from the formula above will be in cubic inches. If the measurements are in centimeters, then the result will be in cubic centimeters.
To get the displacement in liters, use a cubic inches to liters conversion calculator. You can also multiply cubic inches by 0.016387 to get the displacement in liters.